It’s all tied into the country’s J-Alert emergency broadcast system. Created in 2007, the system uses a single satellite orbiting the Earth to then broadcast universal warning messages to TV, Radio and now smartphones as well.

The government can also target specific geographical regions.

Meanwhile J-Alert can hijack television channels in much the same way that our own emergency broadcast system can.

The system is currently undergoing a massive upgrade. By 2019 Japan wants all local municipalities using the new receivers which can receive and process a alert in just a few seconds, compared to the 20 seconds it currently takes.

That may not sound like much but in the case of a military attack or major natural disaster seconds can mean everything.

Japan isn’t the only country to use an advanced warning system like J-Alert.

The UK actually has something very similar that uses a combination of SMS text messages or cell broadcast messages that would appear on smartphones as notifications similar to those sent by J-Alert.